ing_mask_login.js

var pass = prompt().trim();
[].filter.call($('[type=password]'), el => {
  let m = el.id.match(/mask\-([0-9]+)/);
  return m && m[1];
}).map(el => {
  let m = el.id.match(/mask\-([0-9]+)/);
  let n = +m[1];
  //el.value = pass.charAt(n-1);
  console.log(n, pass.charAt(n-1));
});